This phase II study was conducted at 16 clinical centers in China and planned to enroll 150 women with breast cancer who will receive chemotherapy that includes up to 4 cycles of epirubicin and cyclophosphamide, 100 mg/m2 and 600 mg/m2, respectively. Subjects would be randomized to one of three arms, which were 10 mg/dose of F-627, 20 mg/dose of F-627 or Filgrastim, in an equal ratio on Day 1 of the study. Patients will remain on their randomized study drug dose and regimen for each of the following 3 chemotherapy cycles. The chemotherapy to be administered for chemotherapy cycles 2-4 should be the same therapy administered to the subject on Day1.